Q: I have noticed a loud whistling noise coming from the 1st stage on my Xstream regulator, when breathing in it. What is causing this and is it dangerous?
A: A whistling noise can sometimes be heard when the Xstream first stage is pressurized or depressurized. This is due to a resonance frequency which takes place between the ball bearing and the actuating pin. This noise should however not be detectable during low flow rates such as while breathing.
The noise has absolutely no effect on the regulator functionality.

In most cases, the noise can be removed by turning the actuating pin a quarter turn. Contact your nearest Poseidon servicecenter and they can help you with this.

Q: How long is the warranty period on a new Poseidon product?
A: When you buy a new Poseidon product, it comes with a 24 month factory warranty, except those that are regarded as consumables.

Q: How often do I need to service my Poseidon regulator?
A: It depends on how much you dive. If you dive 40 - 50 dives a year, we recommend that you service your regulator once every 24 months.

If you dive more than that, you should service it once every year.

Those that dive every day, should have it serviced at least once every 6 months or so.

Remember that your regulator is life support equipment, designed to keep you alive. If you don't maintain your regulator, it could cause a failure of the equipment.

Q: Can I use a Cyklon, Jetstream or Xstream Deep regulator with nitrox?
A: The Cyklon, Jetstream and Xstream Deep are certified and approved with gas mixes that contains a maximum of 21% oxygen.
The mentioned regulator models have Nitril o-rings and a silicon based lubricant is used, so it's not suitable for gas mixes that have higher levels of oxygen.

If you intend to dive Nitrox, you should use the Xstream Duration, that is approved for gas mixes with a maximum of 99,95% oxygen.

Q: What Poseidon 2nd stages can I combine with what Poseidon Octopus?
A: You can mix Jetstream and Xstream 2nd stages/octopus on the same 1st stage, as these two 2nd stages work with the same intermediate pressure.

But you can NOT mix a Jetstream or Xstream 2nd stage with a Cyklon 2nd stage/octopus. The reason is that the Cyklon 2nd stage works on a higher intermediate pressure than the Jetstream and Xstream 2nd stages.

Mixing Jetstream/Xstream 2nd stages with a Cyklon 2nd stage can be dangerous!

Q: What´s the intermediate pressure on Poseidon regulators?
A: The Jetstream and Xstream regulators should be set to 8.5 bar (123 psi) intermediate pressure, at full tank pressure.

The Cyklon 5000 regulator works at an intermediate pressure of 11,5 bar (166 psi) at 20 bar (290 psi) tank pressure.

Q: Can I use a standard 9/16 LP hose on my Poseidon regulator?
A: If the 1st stage you have, has an over pressure valve built in to it, or has an external over pressure valve attached to a LP port, you can use a standard 9/16 LP hose, if it fits on the 2nd stage connection.

For the Jetstream and Xstream 2nd stages, there is an adaptor available, that allows you to connect a standard 9/16 LP hose to the 2nd stage.

Q: If I put a Cyklon 2nd stage on a Triton 1st stage, do I need to modify the Triton 1st stage in any way?
A: The simple answer is no.

All you need to do, is to adjust the 1st stage to the correct intermediate pressure that the 2nd stage works at.

Q: Why won´t a LP hose fit in the LP port of my old Cyklon 1st stage?
A: On older Cyklon 1st stages, the standard thread size of all ports were 1/8.

Today, all LP ports are 3/8 and all HP ports are 7/16 sized.

If you have an older style 1st stage, there are adaptors that can be used, so you can attach standard sized hoses to your 1st stage.

Male 1/8 --> female 3/8 thread (Article number 2415)
Male 1/8 --> female 7/16 thread (Article number 2910)

Q: What 1st stages can I use the Atmosphere Full Face Mask with?
A: The Atmosphere FFM is CE approved together with the Xstream 1st stage and it's with this 1st stage the mask performs best.

If you intend to use the Atmosphere FFM with another 1st stage, make sure that the correct intermediate pressure is used.

Q: My Atmosphere FFM is vibrating when I breath through it. How can I resolve this?
A: Most likely, you have your FFM connected to a non-Xstream 1st stage or the intermediate pressure on your 1st stage is not correct for the Atmosphere FFM.

Q: Can I put a standard Jetstream 2nd stage on an Atmosphere FFM?
A: The Jetstream PP (the Atmosphere´s 2nd stage) is a modified Jetstream 2nd stage which is constructed to work in conjunction with over-pressure and hold low CO2 levels inside the face mask. Thus you can NOT put a standard Jetstream 2nd stage on an Atmosphere FFM.
Doing that can cause injury or death.

Q: Does my Xstreme regulator have an over-pressure valve in the first stage?
A: The only Xstream regulators that has a built in over pressure valve, are those that has an article number that starts with 0100, complete regulator, or 0110, just a 1st stage.


We have been making regulators since late 50's. We produced the
first single hose regulator - the CYKLON. We came up with the first
300bar regulator. In 2002 we introduced XSTREAM, a regulator that
was produced after much input from the technical diving community.